Conventional bilge and bait/live-well pumps include compact electric motors that drive an impeller and pump water from one location to another. The motors in pumps are typically permanent magnet electric motors which operate on 12 Volt, 24 Volt, or 32 Volt DC power. Upon operating at high load or over an extended period of time, pump motors produce a significant amount of heat, which can affect the efficiency of the motor or, at the extreme, damage the coils of the motor and disable it completely. Proper cooling must be taken into consideration when designing pumps.
Most commonly, bilge and bait/live-well pumps are constructed mainly of plastic, which is a good temperature insulator. This is detrimental to an electric motor that needs to dissipate heat to maintain acceptable performance. This problem has been addressed in the past by providing cooling paths within a plastic pump housing to route water directly to a portion of the motor. However, the motor contains many parts which cannot be submersed in water and must be sealed from the cooling paths, which adds cost and complexity to the design of the pump.